Generally, a probe card tests electrical capacities of a chip on a semiconductor substrate. The probe card makes contact with pads of the chip. The probe card then applies an electrical signal to the pads. The probe card detects a responsive electrical signal from the pads to determine whether operations of the chip are normal or not.
As a semiconductor device has been highly integrated, a circuit pattern of the semi-conductor device has been fined. Thus, it is required to manufacture the probe card having a pitch that corresponds to a pitch of the minute circuit pattern of the semi-conductor device.
Generally, the probe card may be manufactured by bonding a plurality of probes to a bump layer pattern on a multi-layered substrate using a solder paste. The solder paste may be coated by a screen-printing process using a stencil mask. According to the screen-printing process, a pattern is formed on the stencil mask by a laser process, an etching process, an electroplating process, etc. The solder paste passes through the pattern on the stencil mask to coat the solder paste. Here, examples of conventional method for forming a probe card are disclosed in Korean Patent Laid-Open Publication Nos. 2005-109331, 2004-88947, etc.
Here, when a pitch of the bump layer pattern is narrow, an area of the bump layer pattern on which the solder paste is coated may be narrow. Accordingly, an amount of the solder paste may be lack so that a bonding strength between the probe and the bump layer pattern may be weakened. To coat a sufficiently amount of the solder paste on the bump layer pattern having the fine pitch, it is required to increase a thickness of the stencil mask having the fine pattern. However, since the pattern has a small size and the stencil mask also has a thick thickness, the solder paste may not effectively pass through the thick stencil mask. As a result, although the stencil mask is provided with the thick thickness, an amount of the solder paste may be still lack. Further, the solder paste having a tall height may spread due to a gravity force of the probe. The spreading solder paste may cause an electrical short between the adjacent bump layer patterns.
Therefore, according to the conventional method, a sufficient amount of the solder paste, which is required for bonding the probe, may not be coated on the bump layer pattern. In contrast, although a sufficient amount of the solder paste may be coated on the bump layer pattern, the adjacent bump layer patterns may be electrically connected to each other through the spreading solder paste due to the gravity force of the probe.